RT Journal Article SR Electronic T1 Quantification of clot spatial heterogeneity and its impact on thrombectomy JF Journal of NeuroInterventional Surgery JO J NeuroIntervent Surg FD BMJ Publishing Group Ltd. SP 1248 OP 1252 DO 10.1136/neurintsurg-2021-018183 VO 14 IS 12 A1 Yang Liu A1 Waleed Brinjikji A1 Mehdi Abbasi A1 Daying Dai A1 Jorge L Arturo Larco A1 Sarosh Irfan Madhani A1 Adnan H Shahid A1 Oana Madalina Mereuta A1 Raul G Nogueira A1 Peter Kvamme A1 Kennith F Layton A1 Josser E Delgado Almandoz A1 Ricardo A Hanel A1 Vitor Mendes Pereira A1 Mohammed A Almekhlafi A1 Albert J Yoo A1 Babak S Jahromi A1 Matthew J Gounis A1 Biraj Patel A1 Seán Fitzgerald A1 Karen Doyle A1 Diogo C Haussen A1 Alhamza R Al-Bayati A1 Mahmoud Mohammaden A1 Leonardo Pisani A1 Gabriel Martins Rodrigues A1 Ike C Thacker A1 Yasha Kayan A1 Alexander Copelan A1 Amin Aghaebrahim A1 Eric Sauvageau A1 Andrew M Demchuk A1 Parita Bhuva A1 Jazba Soomro A1 Pouya Nazari A1 Donald Robert Cantrell A1 Ajit S Puri A1 John Entwistle A1 Ramanathan Kadirvel A1 Harry J Cloft A1 David F Kallmes A1 Luis Savastano YR 2022 UL http://jnis.bmj.com/content/14/12/1248.abstract AB Background Compositional and structural features of retrieved clots by thrombectomy can provide insight into improving the endovascular treatment of ischemic stroke. Currently, histological analysis is limited to quantification of compositions and qualitative description of the clot structure. We hypothesized that heterogeneous clots would be prone to poorer recanalization rates and performed a quantitative analysis to test this hypothesis.Methods We collected and did histology on clots retrieved by mechanical thrombectomy from 157 stroke cases (107 achieved first-pass effect (FPE) and 50 did not). Using an in-house algorithm, the scanned images were divided into grids (with sizes of 0.2, 0.3, 0.4, 0.5, and 0.6 mm) and the extent of non-uniformity of RBC distribution was computed using the proposed spatial heterogeneity index (SHI). Finally, we validated the clinical significance of clot heterogeneity using the Mann–Whitney test and an artificial neural network (ANN) model.Results For cases with FPE, SHI values were smaller (0.033 vs 0.039 for grid size of 0.4 mm, P=0.028) compared with those without. In comparison, the clot composition was not statistically different between those two groups. From the ANN model, clot heterogeneity was the most important factor, followed by fibrin content, thrombectomy techniques, red blood cell content, clot area, platelet content, etiology, and admission of intravenous tissue plasminogen activator (IV-tPA). No statistical difference of clot heterogeneity was found for different etiologies, thrombectomy techniques, and IV-tPA administration.Conclusions Clot heterogeneity can affect the clot response to thrombectomy devices and is associated with lower FPE. SHI can be a useful metric to quantify clot heterogeneity.All data relevant to the study are included in the article or uploaded as supplementary information. Not applicable.